Ventura County sheriff's deputies found a $201-million marijuana grow operation hidden in canyons north of Lake Piru in the Los Padres National Forest, authorities said Wednesday.

More than 50,000 pot plants, stretching over a mile and into several canyons, were discovered Friday during a reconnaissance flight for drugs, said officials with the Ventura County Sheriff's Department.

The operation is one of the largest single grows the department has ever busted, said Capt. Don Aguilar. Investigators believe six to eight suspects were camping at the cultivation site but fled when authorities arrived.

They left several hundreds of pounds of fertilizer, rat poisons, herbicides and "mountains of trash," according to a department statement.

Water appeared to have been diverted from several natural springs to hand-dug reservoirs. Several miles of irrigation hose was then used to water the plants throughout the canyons.

The growers apparently added fertilizer to the reservoirs, which sheriff's officials said prevents water from flowing to native plants and makes it unsafe for animals and humans to drink.

It's a dangerous situation.— Capt. Don Aguilar, Ventura County Sheriff's Department, on a massive marijuana operation that may have been run by a Mexican cartel

Investigators removed the plants and burned them at a separate location.